s390/pai_crypto: Introduce generic event init using pai_pmu[]

s390/pai_crypto: Introduce generic event init using pai_pmu[]

To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.

Rework PAI crypto event initialization. Add a common
function for event initialization. It uses the PAI characteristics
stored in the pai_pmu table instead of hardcoded values.
Enlarge pai_event_valid() to check all event validation aspects.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>